Thank you for writing.
By default, when you enter a valid text in the editable part of RadMultiColumnComboBox
and open the drop down, the respective row is selected. Please refer to the attached gif file.
Note that you can use the auto-complete functionality that RadMultiColumnComboBox
supports. Thus, it would be easier for the user to enter input. Additional information is available here: http://docs.telerik.com/devtools/winforms/multicolumncombobox/features/auto-complete
I hope this information helps. Should you have further questions I would be glad to help.